The arterial oxygen content (CaO2) definition is the amount of oxygen bound to hemoglobin (1.34 * Hb * SaO2) plus the oxygen dissolved in plasma (0.0031 * PaO2).

The arterial oxygen content equation: CaO2 = (1.34 * Hb * SaO2) + (0.0031 * PaO2).

The normal oxygen combining capacity is 1.39 mls/gram, however due to abnormal forms of hemoglobin such as carboxyhemoglobin and methemoglobin this value is reduced to 1.34 mls/gram.

Hb is Hemoglobin, the normal Hb for males is 14-20 g/dl and females 12-15 g/dl.

SaO2 is the percentage of available hemoglobin that is saturated with oxygen, this value is from a direct measurement of an arterial blood gas.

0.0031 is the solubility coefficient of oxygen at body temperature. PaO2 is the partial pressure of oxygen in arterial blood not bound to hemoglobin.

How to Calculate Arterial Oxygen Content

Hemoglobin Saturation: SaO2 in %:
Hemoglobin: Hgb in g/dl
Arterial Oxygen Partial Pressure: PaO2 mmHg
Arterial Oxygen Content: vol%

Arterial Oxygen Content Calculation

Arterial oxygen content normal values: 16 – 20 vol%

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